Mattress covers are typically utilized to enclose mattresses supported upon mattress foundations. Some foundations are adjustable to vary the shape of the mattress supported thereon in accordance with a user's comfort level. Such foundations are typically operable to incline a portion of the mattress associated with the user's head and shoulders, and/or another portion of the mattress associated with the user's legs and feet. With varying degrees of success, mattresses can be retained in place upon adjustable mattress foundations (e.g., as the foundations are manipulated between inclined and flat configurations) using appropriately-positioned brackets, headboard and footboard sets, bumpers, and the like. However, conventional devices to perform this function often inadequately retain various mattress types in place upon the foundation, require significant structure and hardware, are lacking in aesthetics, and have a number of other shortcomings.